diff --git a/src/Triangle/Configuration.cs b/src/Triangle/Configuration.cs
index 0d2f306..95d5286 100644
--- a/src/Triangle/Configuration.cs
+++ b/src/Triangle/Configuration.cs
@@ -7,8 +7,6 @@
 namespace TriangleNet
 {
     using System;
-    using TriangleNet.Meshing;
-    using TriangleNet.Meshing.Algorithm;
 
     /// <summary>
     /// Configure advanced aspects of the library.
diff --git a/src/Triangle/Meshing/ConstraintOptions.cs b/src/Triangle/Meshing/ConstraintOptions.cs
index 684273e..b531ac6 100644
--- a/src/Triangle/Meshing/ConstraintOptions.cs
+++ b/src/Triangle/Meshing/ConstraintOptions.cs
@@ -6,14 +6,6 @@ namespace TriangleNet.Meshing
     /// </summary>
     public class ConstraintOptions
     {
-        // TODO: remove ConstraintOptions.UseRegions
-
-        /// <summary>
-        /// Gets or sets a value indicating whether to use regions.
-        /// </summary>
-        [System.Obsolete("Not used anywhere, will be removed in beta 4.")]
-        public bool UseRegions { get; set; }
-
         /// <summary>
         /// Gets or sets a value indicating whether to create a Conforming
         /// Delaunay triangulation.
diff --git a/src/Triangle/Meshing/QualityMesher.cs b/src/Triangle/Meshing/QualityMesher.cs
index 13b2fb7..e8e1194 100644
--- a/src/Triangle/Meshing/QualityMesher.cs
+++ b/src/Triangle/Meshing/QualityMesher.cs
@@ -12,7 +12,6 @@ namespace TriangleNet.Meshing
     using TriangleNet.Geometry;
     using TriangleNet.Logging;
     using TriangleNet.Meshing.Data;
-    using TriangleNet.Tools;
     using TriangleNet.Topology;
 
     /// <summary>
diff --git a/src/Triangle/TrianglePool.cs b/src/Triangle/TrianglePool.cs
index f390388..30d866c 100644
--- a/src/Triangle/TrianglePool.cs
+++ b/src/Triangle/TrianglePool.cs
@@ -8,7 +8,6 @@ namespace TriangleNet
 {
     using System;
     using System.Collections.Generic;
-    using TriangleNet.Geometry;
     using TriangleNet.Topology;
 
     public class TrianglePool : ICollection<Triangle>
diff --git a/src/Triangle/Voronoi/BoundedVoronoi.cs b/src/Triangle/Voronoi/BoundedVoronoi.cs
index 303e1ab..472ac88 100644
--- a/src/Triangle/Voronoi/BoundedVoronoi.cs
+++ b/src/Triangle/Voronoi/BoundedVoronoi.cs
@@ -6,12 +6,10 @@
 
 namespace TriangleNet.Voronoi
 {
-    using System.Collections.Generic;
     using TriangleNet.Geometry;
     using TriangleNet.Tools;
     using TriangleNet.Topology.DCEL;
 
-    using HVertex = TriangleNet.Topology.DCEL.Vertex;
     using TVertex = TriangleNet.Geometry.Vertex;
 
     public class BoundedVoronoi : VoronoiBase